A long-term aim of the UICC is to attain an internationally acceptable classification of the anatomical extent of cancer (TNM). The UICC is the only international organization responsible for this project, coordinating and leading the several national TNM committees which carry out specific tasks. The relaxation of coordinating efforts over a period of several years led to the development of "double standards", variations in classification criteria among the participating groups. This became such a critical problem that for the past five years (1982 to 1987), all efforts of the UICC TNM Project and its national TNM committees (including the American Joint Committee on Cancer-AJCC) were directed towards unification. The goal was achieved. A single TNM Classification is now in press from both the UICC and the AJCC. This not only unifies, but updates, the component site-specific classifications based on clinical and pathological data. Furthermore, during the process, TNM classifications were elaborated for sites not previously covered. Five specific goals are considered for the next phase of work in this project: -implementation: to disseminate and promote the universal use of the system; 2-monitoring: to measure user satisfaction or otherwise; 3-testing: to determine validity, especially in respect to new diagnostic and imaging modalities; 4- classification of new tumor types: namely mesotheliomas, visceral sarcomas, small bowel and appendiceal carcinomas, gastrointestinal carcinoids and hepatic and pulmonary metastases; -prognostic grading: to develop an integrated system that will combine the data of anatomical extent of disease with other factors, eg. histologic grade, aneuploidy, biochemical markers, age, sex, immunological response, for a more accurate approach to prognosis than given by extent of disease alone. The costs of the above tasks and studies will be borne by the national TNM committees and are not included in this grant proposal. This grant will only cover the costs of coordinating the work, namely five annual TNM Committee meetings and four editorial sessions.